This project represents an expansion and extension of the Pediatric AIDS Clinical Trials Subunit at the University of Massachusetts Medical School which was funded in September 1990. The principal investigator has been actively involved in HIV care and research since 1983. Over the past four years the Principal Investigator and his collaborators Drs. Barbara Stechenberg and George Johnson have provided care to ever increasing populations of HIV seropositive infants born to intravenous drug using (IVDU) women or sexual partners of IVDU males. Dr. Stechenberg, at Baystate Medical Center in Springfield, has been a co-investigator of the University of Massachusetts Pediatric ACTU Subunit since its inception in September 1990. Dr. Johnson at the University of Connecticut in Farmington, has collaborated over the past year when his NICHD study site became part of the ACTG network in August 1990. Over the past year the three sites which make up the proposed Western New England ACTU have recruited 39 patients into ACTG pediatric protocols. We currently care for 235 infants and children born to HIV seropositive mothers of whom 100 are currently known to be infected. Based on newborn screening for the three regions in Massachusetts (Northeast, Central, Western), and the Greater Hartford area in Connecticut, we can expect 115 infants born to HIV infected women in the next year in our referral area. We can expect approximately 35 of these infants to be infected. The participation in the NIAID/NICHD WITS study and piloting of ACTG 076 provides further support for long term funding of our ACTU for perinatal transmission studies.